1221776 has 20 divisors (see below), whose sum is σ = 2492400. Its totient is φ = 578592.

The previous prime is 1221767. The next prime is 1221791. The reversal of 1221776 is 6771221.

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1706 + ... + 2313.

It is an arithmetic number, because the mean of its divisors is an integer number (124620).

2^1221776 is an apocalyptic number.

1221776 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1221776 is an abundant number, since it is smaller than the sum of its proper divisors (1270624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221776 is a wasteful number, since it uses less digits than its factorization.

1221776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4046 (or 4040 counting only the distinct ones).

The product of its digits is 1176, while the sum is 26.

The square root of 1221776 is about 1105.3397667686. The cubic root of 1221776 is about 106.9047978425.

Adding to 1221776 its reverse (6771221), we get a palindrome (7992997).

The spelling of 1221776 in words is "one million, two hundred twenty-one thousand, seven hundred seventy-six".